Abstract: To reduce frac fluid loss and formation damage and promote frac fluid flowback,Hydraulic fracturing with hydrocarbon dioxide foam was used in Sulige,low pressure and low permeability gas reservoir,to decrease the problem of frac fluid flow back and formation damage caused by conventional water based frac fluid.Hydraulic fracturing techniques with hydrocarbon dioxide foam was studied in the paper.These techniques include foam bubbling,acidic cross-linking,variable foam quality and constant internal phase etc.Through practical application,it showed that it could remarkably improve fluid flow back and frac effect,reduce the duration of flow back and formation damage.